Hydrogen sulfide is a colorless gas with an offensive odor. It is soluble in water and oils. Hydrogen sulfide is often encountered in the oil and gas industry. It can occur naturally as a component of formation gases. Thermal degradation of organic materials and sulfate reducing bacteria (SRB) can also produce hydrogen sulfide. Removal of hydrogen sulfide is warranted because hydrogen sulfide is corrosive, toxic, and flammable.
The process of removing hydrogen sulfide in the oil and gas industry is known as gas sweetening and can be accomplished by either iron sponge H2S scrubbers or chemical scavengers. Typical hydrogen sulfide scavengers used in the oilfield include amine based scavengers such as triazines, oxidants such as chlorine dioxide, amine-aldehyde condensates, metal carboxylates and chelates.
Recently, certain enzymes have been disclosed as efficient biomolecules that mitigate S-based species, such as hydrogen sulfide and mercaptans. For downhole applications, these biomolecules may be injected in a fluid system containing a carrier. Due to the promising use of the enzymes as non-toxic and environmentally friendly hydrogen sulfide scavengers, alternative methods of delivering the enzymes are needed in the art.